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FT-101 Quick Tune-up Procedures

Quick Tune-up Procedures (http://www.qsl.net/nw2m/)

If you have ever purchased a FT-101 transceiver without the Instruction Manual, you know it can be very intimidating to operate until you perform the tune-up process a time or two. Without 'tuning up' your transmitted and received signals really suffer AND could actually damage the tubes in the power amplifier. I always suggest that you download the Instruction Manual for any FT-101 radio or accessory you own. Even older radios have web pages that can provide you copies at very reasonable rates. An Instruction Manual was made for each and every FT-101 radio and accessory. These are free across the Internet. Even the FT-101 Service Manual is available (32MB PDF). See the FT-101 Repair Facilities section on this page for the link. No excuses!

The FT-101 series is a very mechanical radio. The size, selection, and operation of this rig allow for very high-Q circuit tuning. It is a very strong point with the FT-101 series. As with any high-Q circuit, it must be continuously tuned for maximum efficiency. Once learned, it takes only a few seconds to perform. You should re-tune anytime you change bands, change antennas, or move a significant distance (in frequency) from where you last tuned up. This may be as large as 200 kHz on the 10 meter band (10-15 turns of the VFO dial) or as little as 15 kHz on the 160 meter band (one turn of the VFO dial).

Before you begin, you should allow the rig to warm up (with the heaters on) for at least 15 minutes. This allows the rig to become frequency and temperature stable. Put the Meter switch into the 'IC' position with the CARRIER and MIC control fully counter-clockwise. Throw the MOX switch to engage the transmitter and read the meter that is now displaying the idling current. The current should read 60ma on the scale. If it does not, adjust the BIAS control until 60ma is obtained. Move the Meter switch to ALC and ensure a full meter deflection to the right. Adjust the ALC control as needed. Return the MOX switch to normal PTT.

Please remember to tune-up into a well-matched antenna system or dummy load representing a 50 Ohm load. Keep all tune-up steps to under 10 seconds of transmitting to prevent damage to the Power Amplifier tubes! After each 10 second transmission, allow the tubes to cool for 10 seconds. Then repeat. Do not exceed this 50% duty cycle. The tubes can only dissipate 30 watts each! You can put heat into the tubes faster than they can dissipate that heat!

The earlier FT-101 manuals used a tune-up procedure which 'peaked' the output (PO) while 'dipping' the grid (Ic) current. By the FT-101F series, the procedure was simply a 'peaking' (PO) process as depicted in the Instruction Manual. With a little practice, you will be able to perform these procedures within 10 seconds. Really!

Tune-Up Procedure for SSB, CW, and AM:

  • After a 15 minute warm-up, and Idle Current confirmed at 60 ma:
  • Select the band and general operating frequency to be used.
  • Place the Meter switch in the Power Out (PO) position.
  • Rotate the PRESELECTOR for maximum receiver noise/signal output.
  • Place the CARRIER control to position 4 and MIC control to minimum.
  • Momentarily engage the MOX or PTT transmitter control for a maximum of 10 seconds.
  • Adjust the PRESELECTOR, TUNE, and PLATE controls for maximum meter deflection.
  • Disengage the MOX or PTT transmitter control and allow the rig cool for 10 seconds.
  • Increase the CARRIER control two units and repeat.
  • NOTE: If using AM, peak the CARRIER for 30 watts maximum, then increase the LOAD control one unit. The PO meter will deflect slightly on voice peaks.

Adjust CARRIER, MIC, and PROCESS controls for the proper output as desired. Monitor the Meter for grid current (Ic) and ALC levels (ALC) to ensure that you are not over-driving the transmitter. Both will greatly shorten tube life, cause distorted transmitted audio, and is the prime source of television interference (TVI).

AM Operation

One of the most misunderstood and mistuned modes available on the FT-101 transceivers is the AM (Amplitude Modulation) transmitter. (Second only to the RF Speech Processor!) The FT-101 has one of the best on-air signals for AM that you may ever find in a stock radio. It is also one of the easiest to make a mistake. The most common mistake is measuring AM power the same way that you measure SSB or CW signals using a watt meter. AM is very different.

The most common mistake is running too much carrier power in AM mode. The FT-101 can only deliver 30-40 watts of AM carrier in linear service. The reason for this is that an AM signal contains a steady carrier and two sidebands that contain your audio. The amount of RF power in this modulated AM "envelope" is actually 4-times the carrier. This means that a modulated AM signal with a 30-watt carrier is actually transmitting 120 watts of power. This is the amount of power needed from the power supply to transmit this signal. It is also approaching its absolute power limit. The same is true with the matching FL-2100B amplifier. A 300-watt carrier contains 1200 watts of RF power when fully modulated. There is nothing worse than "cooking" a FT-101 by running AM with a 100 watt carrier. The power supply, tubes, and amplifier components cannot deliver 400 watts of power, are run continuously beyond their maximum rating, and for long periods of time. Beware when purchasing one of these 11 meter 'cooked' radios!

Alignment Points and Procedures

As you know by now, the FT-101 series of radios are very mechanical. From time to time, they will require basic alignment and calibration. The Yaesu factory knew this and made many of the adjustment points directly accessible under the top cover. Personally, I let the FT-101 warm-up for 2-hours with the heaters on and covers on so that the unit becomes temperature and frequency stable. Never try to align or calibrate a cold rig.

The FT-101 Service Manual has the most complete description of alignment and calibration information for the FT-101 series. The Service Manual covers all of the models from the original FT-101 thru the FT-101E. Chapter 7 depicts the entire process. There are a few things to remember about the FT-101 radios: 1) They are 40 years old. 2) They are analog radios. 3) They do require alignment from time to time. 4) Parts may be hard or impossible to find. 5) It is a radio without equal!

Be very cautions of cleaners and solvents on this rig. Tuner Cleaner can be used on mechanical switches. Potentiometer Cleaner on all variable resistors. Use Compressed Air on coils and variable capacitors. Whetting these parts and moving them back and forth may actually dissolve that material which provide the resistive function. Residual oils may actually attract more dirt and dust over time. Solvents should NEVER be used!

There are a few terms you need to know about, how to correctly use, and apply them. Please note that there are many WRONG descriptions on the internet including videos on YouTube. Follow them (with respect to the FT-101) and you are going down the path to mistakes and frustration. Let's get started:

Zero Beat (#1) This is the term used when the absolute value of a single tone is adjusted to zero. This occurs when you hear the high-pitched FT-101's internal MARKER tone and you adjust the VFO so that the tone goes lower and lower in frequency until it is no longer heard thru the speaker. Since the frequency you hear rolls off at 100Hz (you can no longer hear the tone), you go just a fraction more to account for the last 100Hz that you cannot hear. The goal is truly zero-Hz. This is how you adjust the VFO to the MARKER when you: Change Bands or Change Modes (eg: USB to LSB, or from CW to USB, etc.). After you Zero Beat the VFO with the MARKER, you rotate the silver frequency wheel to align with the 25kHz or 100kHz multiple. This puts the FT-101's VFO on-frequency. The MARKER is calibrated with WWV. It is your master frequency standard on all bands.

Zero Beat (#2) This is a term used when you adjust two tones to be equal with each other. It is like tuning a guitar. It is not finding the average between two single tones as you flip some switch back and forth. When you Zero Beat two simultaneous tones being emitted from the FT-101, you will eventually hear the famous "wow wow wow" as the two tones "beat" against each other. As the tones get closer together in frequency, they become indistinguishable to the human ear- and the wow-wow ceases. You have achieved the Zero Beat process. Here is an audio example of the process. At the end of the audio clip (25-28 second mark), the tone is steady. These are the tones you will hear when setting the 10 MHz MARKER used to provide the 100 kHz and 25 kHz Markers. You will Zero Beat the WWV radio signal with the FT-101's MARKER. This will provide an accurate internal frequency reference. The goal is to mimic the highly accurate over-the-air 10MHz radio frequency emission from WWV in Colorado. Adjust the MARKER trimmer capacitor with a non-metallic tuning tool. This trimmer capacitor is labeled "MARKER TC1" on the FT-101 Top Chassis Photo.

WWV The radio station WWV plays a vital role with the FT-101 series radios. WWV transmits a highly accurate frequency carrier at exactly 10 Mhz. This signal is received by the FT-101 radio tuned to the WWV Band segment and is ultimately used to zero-beat with the internal MARKER frequency to derive accurate frequency calibration. Since WWV transmits like any other radio station, it will not be heard all the time. It may take several attempts to get a strong S7 on the FT-101's meter to perform accurate MARKER calibration. Be patient. This is typical of radio signals in the 30 Meter band, your distance from Ft Collins Colorado, time of day, solar activity, and the effectiveness of your antenna.

Three sub-models:

"Early" - S/N 15,000 and lower. (PB1494) Processor

"Mid" - S/N 15,001-20,500. (PB1534) Processor

"Late" - S/N 20,501 and up. (PB1534A) Processor, (PB1547A) Regulator, (PB1183C) IF, (PB1315B) Audio, (PB1582) Blanker.